Nuclear Energy for Tomorrow

Nuclear energy already is a mature technology, benefiting from several
decades of development and industrial experience. It has the potential
for contributing to future sustainable supply of energy services, taking
advantage of feedback from past experience and ongoing R&D programmes
on advanced systems.

The future of nuclear energy will depend on the evolution of the broad
social and economic context and on technology progress and breakthroughs
that will be achieved. Reviewing the present status and trends in the
field of nuclear energy provides some insights into its future prospects.
A rapid survey of recent achievements in technology progress and R&D
programmes complements the overall picture of nuclear energy potentials
and its likely future. Both past experience and ongoing activities illustrate
the benefit of international co-operation and the role of international
organisations such as the OECD Nuclear Energy Agency.

Nuclear energy today

Nuclear energy has moved from the discovery of fission to a mature
technology commercially deployed in many countries over a relatively
short period of time. The first kWh of nuclear electricity was delivered
to the grid only some 50 years ago, and today nuclear energy contributes
to energy supply in more than 30 countries, including 16 OECD countries.
More than 10 000 reactor-years of commercial operation experience,
including 8 000 reactor-years in OECD countries, have been
accumulated.

By the end of 2001, some 438 nuclear power plants were in operation
in the world, representing an installed capacity of 353 GWe, supplying
some 6% of total primary energy consumption and around 15% of total
electricity generation. Some 80% of the total nuclear capacity is operated
in OECD countries, where the nuclear energy share is higher than worldwide,
corresponding to nearly one quarter of total electricity generation.

It is important to note that nuclear electricity generation, being
practically carbon free, contributes to alleviating the risk of global
warming and climate change. So far, in OECD countries, nuclear energy
has been a main factor in reducing or stabilising greenhouse gas emissions
in spite of growing energy consumption. Globally, nuclear-generated
electricity is responsible for reducing greenhouse gas emissions from
the energy sector by some 8% each year. Furthermore, nuclear power plants
and fuel cycle facilities require less land and water than most other
energy systems and do not release particulate matter or gases, such
as sulphur and nitrogen oxides, responsible for acid rain, urban smog
and depletion of the ozone layer.

The contribution of nuclear energy to diversity and security of supply
is also worth noting. Nuclear energy alleviates dependency on hydrocarbons,
a key driving factor in energy policies of some OECD countries, such
as Japan or France where oil and gas reserves are insignificant. Security
of supply is an intrinsic characteristic of nuclear energy since nuclear
fuel is easy and cheap to stock and uranium resources are widely distributed
in the world.

Current trends in the field of nuclear energy are characterised by
a very modest growth in the number of plants in operation, although
nuclear installed capacity and electricity generation continue to grow
owing to plant up-rating and increased capacity factors. Only a few
new nuclear power plants are under construction or being planned in
OECD countries, mostly in the OECD Pacific region, Japan and the Republic
of Korea. In Europe and North America the plans are to continue operating
existing plants, often beyond their originally licensed lifetime and
a few countries are starting to contemplate ordering new units, led
by Finland. Some countries such as Belgium, Germany and Sweden intend
to accelerate the closing down of their plants.

However, nuclear energy technologies are progressing steadily owing
to R&D and development programmes supported by governments and the
industry. Continuing technology progress and feedback from experience
are leading to enhanced performance of nuclear power plants in operation.
Trends in average capacity factors are illustrative of this progress
with an increase of more than 8% between 1990 and 2000, from 77.2% to
85.9%. In the United States, the average capacity factor of the 104
reactors in service reached 89.7% in 2001 and would have been 90.7%
if Browns Ferry 1 - which has not been operated for many years although
it holds an operating license - was excluded.

Authorised lifetime extensions, for example beyond 40 years in the
United Kingdom and up to 60 years in the United States, are an indicator
of industrial maturity and robust technology progress. Refurbishment,
safety upgrades and life extension will allow nuclear energy to maintain
a competitive contribution to global supply up to 2020 and slightly
beyond. Further on, however, a new generation of nuclear systems will
be needed.

Since the first deployment of nuclear energy systems, constant progress
has been achieved regarding safety, health and environmental protection.
Examples illustrating enhanced safety and health protection performance
include the decrease in unplanned automatic scrams and industrial safety
accidents. According to the data collected by the World Association
of Nuclear Operators (WANO) covering more than 400 nuclear units in
2000, unplanned automatic scrams per 7 000 hours critical
went from 1.8 to 0.6 between 1990 and 2000.

Throughout the world, occupational exposures at nuclear power plants
have been steadily decreasing since the late 1980s as shown by the data
collected through the Information System on Occupational Exposure (ISOE),
jointly managed by the NEA and the IAEA. The average collective dose
per reactor for all operating reactors included in ISOE, representing
88% of the commercial nuclear reactors in operation worldwide, followed
a downward trend from 2.5 man.Sv in 1987 to around 1.2 man.Sv
in 1999.

In the OECD countries, industrial nuclear facilities have excellent
records regarding global safety and trends show continued progress in
this regard. The industrial safety accident rate tracks the number of
accidents resulting in loss of work-time, restricted work or fatalities.
Worldwide, this rate went from 5.50 per million man-hours worked in
1990 to 1.63 in 2000.

Regarding environmental protection, the decrease of solid radioactive
waste volumes is an important indicator of improved performance. WANO
data show an average reduction by a factor of three over the last decade,
from 108 m3/unit in 1990 to 39 m3/unit
in 2000. Fuel cycle facilities have experienced similar trends in the
reduction of volumes and activity of nuclear waste.

The competitiveness of nuclear electricity depends not only on the
performance of nuclear power plants and fuel cycle facilities but also
on the prices of alternatives. The volatility of hydrocarbon market
prices has been a driving factor in the evolution of nuclear versus
fossil-fuelled electricity cost ratios from the 1970s to the end of
the last century. While the relatively low fossil fuel prices prevailing
today are challenging the competitiveness of alternative sources, such
as nuclear energy, the successive oil crises have highlighted the potential
benefits of diversity and security of energy supply that are provided
by including non-fossil fuel options.

Existing nuclear power plants are competing very well in deregulated
electricity markets, as demonstrated by the experience of several OECD
countries. Their low marginal costs and high reliability give nuclear
units an advantage in open markets. In the long run, once capital costs
have been incurred, nuclear units become the cheapest electricity source
in many countries. Nuclear energy may become even more competitive if
and when national policies will be implemented to internalise external
costs, such as climate change and other environmental burdens. Indeed,
since the price of nuclear electricity already internalises in most
countries the cost of decommissioning nuclear facilities and the disposal
of high-level waste, its external costs are very low compared to those
of most alternatives.

Advanced nuclear energy systems available today

Nuclear power plants under construction and planned, as well as reactor
concepts ready for commercial deployment, include a number of advanced
evolutionary concepts and some more innovative systems. This generation
of reactors and fuel cycles, although largely based upon existing technologies,
integrates lessons learnt through the past operation of nuclear systems
and a broad range of improvements in design, safety, reliability and
economic aspects. The main goal of those systems is to generate electricity
in a safe and reliable manner at low cost.

More efficient use of natural resources and waste minimisation are
important parameters also taken into account in new designs. Efficiency
improvements may be obtained by various means including high-temperature
reactors, high burn-up fuels and the recycling of fissile materials. Finally,
some high-temperature reactors open additional markets.

Examples of advanced nuclear systems that are being built or could
be commissioned before 2010-2015 include advanced light water reactors
(e.g. ABWR, AP600/1000, EPR), advanced pressurised heavy water reactors
(e.g. CANDU NG) and high-temperature gas-cooled reactors (e.g. Pebble
Bed Modular Reactors). A number of other water reactor concepts, liquid-metal-cooled
reactors and advanced fuel cycle options are at similar stages of development.

Recognising that high capital cost is a major barrier to a larger
commercial deployment of nuclear energy, designers of advanced systems
have implemented proven means and adopted new approaches to reduce those
costs. Key elements in this regard include streamlining designs, relying
on passive safety and moving to risk-informed safety, developing digital
instrumentation and using components with built-in diagnostics.

A number of advanced evolutionary designs, such as most of the advanced
water-cooled reactors, take advantage of economies of scale for reducing
capital costs, while other more innovative approaches based upon modularity
and factory building are adopted by others, such as high-temperature
reactors. The former favours large units, 1 GWe and more, the latter
aims at small units, around 100 MWe, that may be connected to a
small grid but could also be built as multiple unit stations in large
networks.

Other means to reduce the capital costs of advanced nuclear systems
include enhanced construction techniques. Construction time has a direct
impact on capital cost through the interest paid during construction
and an indirect impact on financial risk and profitability by delaying
the commissioning of the plant and thereby the revenue flow. Methods
for reducing construction time adopted for nuclear power plants built
recently and proposed for evolutionary advanced reactors include the
use of modularisation and prefabrication of civil structures and components
and slip-forming techniques.

Regarding safety, the defence-in-depth concept remains the overriding
strategy to meet the requirements of increasingly stringent regulations.
The trend in new innovative designs is to ensure a higher degree of
independence between the successive levels of defence in depth. Also,
emphasis is placed on improvements aiming at avoiding the need for off-site
emergency measures in case of accidents.

Waste minimisation is not a high priority for most advanced designs
but improved efficiency, motivated primarily by economic objectives,
contributes to reducing fuel consumption and thereby the weight of solid
radioactive waste arising. Advanced technologies for radioactive waste
and spent fuel conditioning and management can reduce the volumes and
in some cases the toxicity of nuclear waste to be disposed of in final
repositories.

Innovative technologies for tomorrow

A review of ongoing R&D programmes on new nuclear energy systems
shows a wealth of ideas and projects covering a wide range of technical
options and development stages. This was demonstrated, for example,
by more than 100 responses to the call by the USDOE in 2001 for
information on new, innovative nuclear energy systems under investigation
or development.

R&D efforts under way on nuclear energy systems cover a broad
range of reactor technologies and fuel cycle options and rely on a wide
variety of evolutionary and innovative approaches. Concepts considered
by research teams range from classic water-cooled reactors incorporating
innovative options, such as the integral pressurised-water-cooled concepts,
to radically non-classical approaches such as vapour core, molten-salt-cooled
reactors, through high-temperature reactors and liquid-metal-cooled reactors with advanced fuel cycle options such as pyroprocessing technologies.

Several international initiatives have been launched recently to address
the challenges facing nuclear energy. Innovative reactor and fuel cycle
concepts considered in those frameworks aim at achieving excellent performance
in terms of economics, environmental protection, safety and reliability,
and non-proliferation and physical protection. Also, specific attention
is devoted to responding to public concerns in order to facilitate the
deployment of nuclear energy. The major objective of international endeavours
is to strengthen co-operation and the overall efficiency of programmes
aiming at the development of the next generation of nuclear energy systems.

A project on innovative reactors carried out jointly by three international
agencies, including the NEA, proposed a methodology to assess opportunities
for cross-cutting multinational or international R&D in support
of innovative designs offering potential for the future. The approach
adopted for assessing the expected performance of innovative reactor
designs focused on reviewing six key characteristics: safety, economic
competitiveness, proliferation resistance and safeguards, waste management,
efficiency of resource use and flexibility of application. The findings
and recommendations of the project included strong encouragement of
cross-cutting R&D, in particular on enabling technologies, and international
co-operation.

Several countries sharing a common interest in R&D for the next
generation of nuclear energy systems, have established, linked to a
USDOE initiative, the Generation IV International Forum (GIF) as a framework
for international co-operation in the field. Ten countries are Members
of GIF at present, and the NEA, the IAEA and the EC are participating
as observers. During the present phase of the project, the NEA is providing
technical support to some of the GIF working groups. When co-operative
R&D projects will be implemented, it is anticipated that the NEA
could be asked to serve as the Secretariat to some of them.

The first phase of the GIF initiative is to establish a road map for
R&D programmes aiming at the development of a next generation of
nuclear energy systems that can be licensed, constructed and operated
in a manner that will provide a competitively priced and reliable supply
of energy while satisfactorily addressing nuclear safety, waste, proliferation
and public perception issues. The six to eight concepts that will eventually
be selected for further co-operative R&D efforts are intended to
offer high potential to reach these objectives and a reasonable likelihood
to be available for deployment by 2030.

The goals of this next generation of nuclear energy systems as defined
within GIF are: sustainability, safety and reliability, economics, and
non-proliferation and physical protection. A methodology has been developed
to evaluate concepts against those goals using a set of qualitative
and quantitative criteria. In addition, the specific capabilities of
various concepts to efficiently produce process heat, potable water
and/or hydrogen, and to facilitate the management of waste will be taken
into account in the selection of systems offering the highest potential.

Concluding remarks

In a world that will need increasing quantities of energy and will
want to preserve its environment, nuclear energy has large potential.
It can supply a significant share of the energy products that people
will need, such as heat, electricity, hydrogen and potable water, at
affordable costs and without jeopardising natural resources and the
environment. Realising the potential of nuclear energy, however, will
require sustained R&D efforts covering a wide range of disciplines
and technologies.

Ongoing R&D programmes on nuclear energy systems for the future
are focusing on responding to society's needs and concerns. Accordingly,
efficient use of natural resources, reduction of volumes and toxicity
of radioactive waste, and safety systems minimising the risk of off-site
impacts of accidents are key goals of innovative nuclear reactors and
fuel cycles.

International co-operation offers unique opportunities to maintain
a significant R&D momentum while controlling costs in an increasingly
competitive economic context. One of the key added values of international
endeavours is to bring synergy and enhance the efficiency of national
programmes. Pooling resources together and carrying out jointly capital
or manpower intensive studies not only reduces the cost for each participant
country but also offers opportunities for creating more dynamic scientific
teams in a multicultural environment.

The role of intergovernmental organisations such as the NEA is important
in this regard. Given its experience in joint projects and its structure
adapted to international co-operation, the NEA can play an important
role as a catalyst in support of ambitious R&D endeavours for a
successful future of nuclear energy. The expertise and management skills
available within the NEA Secretariat can provide interested Member countries
with a robust and flexible framework to efficiently carry out background
studies and co-ordinate research projects undertaken by various national
teams and laboratories.

Eventually, however, civil society's perception of nuclear energy
and its risks compared to alternatives will be a driving factor in the
choices between different sources and technologies and future energy
mixes.